Oil burning furnace



Nov. 8, 1932.

F- A. HEATH OIL BURNING FURNACE Original Filed Feb. 1 o, 1928 2 Sheets-Sheet '1 INVENTOR ATTORNEY Nov. 8, 1932. A, HEATH 1,886,675

OIL BURNING FURNACE 7 Original Filed Feb. 10, 1928 2 Sheets-Sheet 2- Patented Nov. 8, 1932 i FORREST HEATH, OF UPPER MONTCLAIB, NEW JERSEY OIL BURNING FURNACE Rnssuw Application filed February 10, 1928, Serial No. 253,271. nenewed larch 18,1980.

cerns oil burning apparatus of the class in which metered, and more or less mixed oil and air are sprayed, preferably centrifugally above a refractory hearth that closes in the lower end of a fire box and more specifically to apparatus having the oil projecting means and the hearth organized and operating in such combination that in normal full operation as well as at starting, the flame line or region where active combustion is precipitated is localized adjacent the periphery of the hearth which thus functions as the burner. My present invention also contemplates the use in such a combination of certain features of my prior invention, disclosed and claimed in said companion application, ineluding some of the features of the hearth, which are herein claimed only in combination with certain modifications and additions whereby my present hearth is even better adapted to improve the certainty and speed of ignition; to lessen the danger of having the ignited oil flame put out by being smothered in excess gas evolved at starting; and, in normal full operation, to more certainly localize at the periphery, the zone where active combustion is precipitated.

One feature of said application adapted to my present invention concerns having the periphery of the hearth formed with vertical impingement surfaces of fire brick or the like, adapted to aflord catalytic surfaces to precipitate combustion at the periphery after the refractory material gets highly heatedin normal running. One or more such impingement surfaces extend upward to or above th highest horizontal level to which the oil can be projected by the projecting apparatus, so

that most of the unatomized drops of the projected oil impingesthereon. In my prior application. this impact and ignition wall is closely adjacent the wall of the fire box and operates like a burner from which the flame rises in contact with said fire box wall. My present invention contemplates rearrangements'and additions whereby this somewhat primitive burner is evolved into a more definite type of burner adapted to dischar e flame more directly on the wall to be heate .One feature is spacing this wall inward so as to leave a small space between it and the wall to be heated. It has been found that such rear space when properly designed, is hi hly im portant as a means for deflecting t e blast of flame and combustible mixture into contact with the wall of the furnace. In practice, the combustible'draft from the rotary projector is deflected upward by the impact and ignition wall so that it shows a tendency to curl back away from the wall toward the center portions of the fire box, but it may be readily understood that when such upward draft blast passes the upper margin of a wall having a rear space, the blast tends to draw a vacuum in said space, thereby causing the flame and combustible mixture to curl or eddy back behind the impact wall. Because of such operation, said space may be converted into a sort of reverberatory furnace by adding a refractory wall adjacent the rear face of the impact wall. Thus arranged, the adjacent faces become white hot, promoting perfectcombustion, even though the flame and draft therefrom pass immediately into contact with the relatively cold walls of the water leg of the boiler. While the vacuum and eddy producing efi'ect of the space behind the impact wall is inherent, my present invention includes the further feature of having the spaced apart cooperating refractory wall, forwardly sloping and provided with rearwardly directed reticulations through which the flame may be definitely directed upon the wall to be heated. The space between the front of this cooperating refractory wall, in

reverberatory relation to the rear surface of the impact wall, becomes a hot gas generating region, and if the rear wall is forwardly sloping, the reticulations will .ause the rear face to function like a multiple gas jet burner, the jets whereof are directed against the water leg to be heated. In the'l'atter particular it is analogous to a Welsbachmantle when oversupplied with gas and air mixture.

In the form shown, tlie rear wall of this reverberatory space extends forward far enough to overhang the vertical impact surmore collecting gutters or grooves adjacent the base of the impingement surface, said utter or dgutters being of cross section sufficient to hol all of the unignited oil that can collect during the starting period. This peripheral tter may be a pronounced roove, of depth ependent on the area of t e im in'gement surface draining thereto, so that t e exposed to surface of the oil collected therein is o relhtively small area.

Another feature cooperating well with the, collecting gutter, but which may be sufficient in itself, is to provide for an out drainage of the hearth-downward from the oil projector to the periphery. Preferably, the upper surface of the hearth-is sloped so that it will be close to but substantially out of range of the trajectory of the lowest art of the projected oil. Where such down s ope hearth is used, it forms a collecting annulus or gutter where it meets the base of the vertical or upwardly extending surface of a peri heral imact wall. In the present case, the own slope hearth drains into such a collecting annulus adjacent a very low vertical surface, the main impact wall and its gutter being further on toward the periphery. It is just as well or even better to have the drainage from the hearth into a gutter. In either case, the down slope plus the gutter mutually cooperate to produce the best results, the down slope tending to keep the hearth free fromimpingement of unignited oil and facilitating outward drainage of any that does impinge, while the gutter tends 'to minimize the exposed surface of the oil collected therein.

As explained inmy companion application, this makes it possible tostart with the oil projector projecting only the amount of oil necessary for normal running and yet accumulate at the periphery where it is to be ignited, an ample supply of oil, in even less time than wouldbe possible by an over-supply of oil projected upon the usual up-slope or horizontal hearth which does not have any peripheral gutter. Thus the oil is concentrated at the desired ignition point so that it is readily ignited. Moreover, after it is ignited, the excess oil volatilizes gradually from the surface downward. There is no large area of oil on the adjacent hearth, where it would be volatilize/d by the flame in quantities suflicient' to smother the growing flame and put out the ilot light or ignition torch.

The a ove and other features of my invention will be more evident from the following description in connection with the accompanying drawings, in which Fig. 1 is a vertical sectional view of the hearth and burner, the surrounding fire box and water leg;

Fig. 1a is an enlarged sectional detail showing more clearly and fully the fan and draft arrangementsof the burner head.

Fig. 2 is a plain view of'the burner;

Figs. 3 and4 are enlarged elevations of the refractory burner structural elements; and

Fig. 5 is a section on the line 55, Fi 4.

The furnace to be heated is shown in ig. 1 as including a wall or casing 1, closing in a space which may be approximately the same as the ash pit space of an ordinary coal fire furnace. This supports the furnace which may be of any desired constructionfthe essential partsshown in Fig. 1 being the wall 2 closing in the fire box and an outer wall 3 affording an interspace-4 for the water or air to be heated or boiled, as the ca we may be. An annular ledge 5 supports a plate or metal ,hearth pan 6, stiffened by radial ribs 6a.

This supports a refractory hearth 7 through which projects an air and oil projector conventionally indicated at A.

The hearth is formed at its periphery with the vertical :1 ition wall 8 having at the base thereof an 011 collectin gutter, in this case a groove 9, the depth 0 which is about equal to its width. In the present case the hearth elements are set so that there is a s ightly projecting vertical surface 10 just inside of and parallel with the gutter 9 which is at the foot of the main ignition impact of ignition wall 8. When so set, as it sometimes is, on hearths of small diameter, and when used in combination with the outwardly down sloping hearth, any drainage from the hearth will be to the annular collecting space 10a at the foot of this wall. It will be understood, however, that in many cases the rim of the gutter 9 will be set flush with the upper surface of the hearth.

I ition torches 11, 11 are set in position to disc arge ignition flame across the utter 9 and against the ignition wall 8, and i there is a smaller wall 10 as shown, part of the flame will play upon this wall also.

Various examples of oil and air projectors suitable for my purpose arenow well known.

One'is the oil projector invented by Homer,

A. Tiffany, for which application for letters patent has been'or is about to be made, and another is set forth in my application Ser. No. 47,709, filed August 3rd, 1925, which has resulted in Patent No. 1,707,474, issuedApril 2, 1929. The former is the one conventionally indicated herein.

The oil is centrifugally discharged in an extremely fine spray or vapor through nozzles 12, supplied through a head 13 mounted on vertical shaft 14 which isan extension of an armature shaft of. an electric motor contained in the casing A. This motor is of the usual construction and rotates the head at volume fan tending to create a vacuum in t interior space a. The four nozzles 12 constitute another fan creatin suction at e, and through annular passage this suction takes efiect in the same space that the fan 15 draws from. The air inlet to this space a is through a. slot 6 communicating with the ash it. The cross section of this slot may be a justably decreased or increased by vertical slide 0. Thus, the many blades 15 and the four nozzles 12 constitute two fans drawing in from the same source. The respective suction effects of these two fans are very nearly the sameybut the amount of air delivered through 12 is much smaller than delivered through 15, because the flow section of the four little nozzles'is very much less than that ,of the annulus through which blades 15 dis:

charge.

In operation, oil is supplied to the trough e through a suitable interior nozzle not shown. Centrifugal force causes a film of this oil from trough e to creep up thewalls and ultimately to be thrown ofl as a fine spray projected from the rear lips of the four nozzles 12. Centrifugal force also causes a relatively small volume of air to be projected through these nozzles 12 While a much larger volume of air is being projected by the fan blades 15. The nozzles project substantially above the plane of the top plate 13 of the rotor. Consequently, said plate, together with the upwardly projecting surfaces of the nozzle, constitute in effect a third fan whereby hot "products of combustion are projected in the same horizontal plane with the spray. The projected products of combustion and the air enveloping the spray lose velocity more quickly than the spray, so that the spray tends to cut through the paths of the former.

Thus the composite draft produced by the nozzles consists of a mixture of hot products of combustion, spray and a small percentage of air. When this composite mixture strikes the periphery of the hearth, the spray is further atomized and mixed with the primary air and gas and also with the air from the fan blades. These easily ignite, at starting, and when the apparatus is in full operation so that the refractory impact surfaces are at high heat, the combustion at the periphery is substantially perfect. The oil and air supplies to the burner, as also the means for metering the same, form no part of my presentinvention and are not shown." Similarly,

arallel tions per minute sizes of furnaces and all degrees of heatf the means for controlling supply of gas to the ignition torches 11 maybe of any known or usual construction and are not shown. The important features are that the ignition torch nozzles 11 are locatedinside the circumference of the collecting groove and the flame therefrom impinges along the ignition wall, preferably in the same direction that the rotary head tends to rotate the body of air or gaswithin the fire box. I have discovered b many experiments that an outward down s ope for the hearth of ap roximately inch to the foot is sufficient to eep the upper surface below the trajectory of the oil, even when the diameter of the fire boxis a maximum. As a specific illustration of preferredconstruction, I may note that an 8-inch rotary head 12, 13, may be utilized for fire boxes of widely varyin diameter simply by varying the'metering o the oil and gas, a uniform-running s eed of, say, 1700 revolu eing maintained for all Where such a head is used in a fire box having a hearth only 24 inches in diameter, the oil only has to be thrown 8 inches. In such the collecting groove alone may be sufficient without the slope. With greater diameters, the outward down. slope is progressively of greater importance, but for all sizes of hearth up to, say, 8 inches in diameter, the standard outward down slope of inch to the foot is sufficient.

So far as concerns the main impact surface or surfaces and the gutter, it will be recognized that they correspond to similar parts in my companion application, but as above described, their functioning after they get hot, in full normal operation, is combined with and modified by additional arts and features of construction whereby t e simple wall and groove burner becomes more a gasifying and mixing region furnishing gas to and through other elements which have a more characteristic burner function.

The entire peripheral construction is built up of relatively short molded sections of fire brick or other refractory catalytic material.

As the cross section is substantially uniform F.

except at one point to be mentioned hereafter, these sections'may be made as standard molded units which may be assembled to fit any desired diameter or shape of furnace. In. the

form illustrated in Fig. 2, the fire box is square and similar units in varying lengths are sawed or otherwise formed to fit as at a, b, c, (1, etc. As shown on sheet 2 of the drawings, the units preferably comprise a base member 9a, affording the gutter 9 and afford- Gal ing also a support for an integral upright element 82L. In the rear of this is a relatively small space or cavity arranged so as to be vacuumized by the draft deflected upward by impinging on the front wall of said element, whereby in normal operation the flame and combustible mixture tends to curl and eddy backward into said space, as above described. In the form shown, the rear face 86 slopes downward at a relatively steep angle to a flat surface 80 and has integral therewith upstandin ribs 8d, affording a support surface 8e, pre erably parallel with 86, and a ledge or stop, 8f.

In this form,-the cooperating reverberatory surface is afforded by utilizing the supfport surface as a spacer and support for a re ractory burner slab 18, sloping upward and projecting over the wall '8 a considerable distance, so that its free edge 18a is vertically beyond the gutter 9. This slab has burner passages or reticulations 18b.

The relative areas of the surfaces, as well as the area and angle of the overhang 180 admits of considerable variation, but the object is first to intercept all of the unatomized drops upon the refractory faces resented toward the center ofthe hearth an while most of it is preferably received upon the surface 8 and drains directly into the gutter 9, it is evident that scattermg drops may be intercepted by the burner plate 18 and if the hearth projects as at 10, some drops may fall on this vertical surface. Dro s striking above the surface 8 will natural y drain or be blown by the air draft rearward to the space behind the burner structure. For this reason, I prefer tohave the area surface 8f, Fig. 5, spaced slightly apart from the fire box wall 2. Any oil draining to thispocket will be practically out of the field of operations during the starting period, but afterthe a paratus is in full operation, this oil will e volatilized and burned so that no reat .excess accumulates. In order to provi e a path of escape for any such excess, I arrange a. slot-like passage 8w, whereby this space drains down the surface 83 into the gutter 9 in front of the ignition surface 8.

Another factor controlling the propertions of the parts, particularly the angle and overhang of the burner plate at 18a and the height of the supports 8e is to have the horizontally discharged blast from the projector pocketed and deflected so that it will be discharged partly through the burner reticulations 18?), and partly downward along the surface 86 directly to the fire box wall 2.

These things will be further explained fromthe operation of the apparatus which ma be described as follows: F

e usual controls are employed whereby power is supplied to rotate the head 13 to deliver a predetermined metered suppllyl of oil along the lines :12, y and air or air and ot gas,

as indicated by the arrow 2, the oil projected against ignition wall 8 collecting 1n groove 9. Some of it may be 'pro'ected under or through the slab 18, but this rains rearward 1y as described above. The maximum exposed surface of oil is therefore practically limited to the area of the exposed burner sur-' faces plus the upper surface area of the oil in groove 9. All of the oil being concentrated in the ignition region, th igmtion torches quickly ignite the oil around the entire riphery, ut any increased oil surface tligt such i nition brin 's into play, is above and beyon the zone of the ignition surface and gutter, there being little, if an oil on the upper surfaces of the hearth. onsequently, the igniting operation is quick and uniformliy progressive until the entire periphery ames. Any oil on the overhang or under surface of burner plate is in the best ossible position to intercept and be vaporized growin blaze from below.

It W1 1 be noted that during the ignition period, the combustible blast mixture is. deflected through the burner and cleared of excess'oil drops carried thereby, thus tending to correct the natural over-richness of the mixture at this stage when so much oil is being evaporated from the wet surfaces. The burner plate 18 and particularly the overhang portion thereof, being jthin, quickly become incandescent, as also the th n up-.

wardly tips and edges of the pro'ectin su ports 8d. Later on, all of the urfac es b come hot enough so that in normal running all oil droplets are vaporized immediately upon impact with the burner surfaces.

by the Another very important function of the burner plate is that of a homogenizing mixer.

The blast from the projector nozzles is more or less finel subdivided or atomized spray.

The air is elivered below the spray by the.

fan and naturally tends to crossthe path of the spray and formswith it, a combustible blast that carries on its upper surface an admixture of burned out gas rich in carbon dioxide. This three-fold mixture projected against the burner is thoroughly baflied and homogenized as part of it is driven through the reticulations of the burner-plate and part is deflected downward and rearward under the plate. The advantage of such a homogeneous mix ture is well known and the special advantage of the carbon dioxide diluent is also well known as conducive to a voluminous flame of less intensity but much greater heating effect as concerns the fire wall 2. In normal full operation, my present invention makes it possible to cut down the air to just the amount needed for complete combustion with the ref suIt that the flame may be almost invisible like the blue part of the flame from a well regulated Bunsen burner. An important feature is that this flame is directed through the burner plate and downward under the na seous .is turned off and the oil flame dies down, it

naturally shrinks down behind the ignitlon wall to the surplus oil there collected and then follows the draining oil through the slot 8w into the groove, thus relighting the ignition torch before itself becoming extinguished. Or if the ignition torch is'intermittently operated by a pilot light projecting upward in the groove 9, as in my companlon apphcation, it will be the pilot that is regulated in this way.

While I have shown the firebox as belng square, it is to be understood that In practice ,they are often oblong orcircular. In such cases the peripheral-burner preferably follows the fire box wall in the relation indicated in cross section in Fig. 1, although it is desirable to have it cut across the extreme angles of the corners as shown.

I claim:

1. Apparatus of the class described, including a furnace, a hearth closing in the bottom thereof, and a centrifugal projector radially discharging a composite draft of air adj acent the upper surface of the hearth and oil above the air, said projector and hearth being designed and operating to initiate combustion in a peripheral zone of im act and disturbance of the projected composlte draft; and, extending along said peripheral zone, a homogenizing burner of refractory material formed with an upwardly extending wall having inwardly presented impact surfaces adapted to intercept the path of the projected oil and deflect the draft upward, an oil collecting gutter in drainage relation to said impact surfaces, a rear oil collecting gutter behind said wall, a drainage passagedraining from said rear gutter to the front of said wall, and a re-ignition gas jet in position to be ignited by flame communicated through said passage when normal operation is discontinued, in combination with an outwardlyand downwardly sloping burner plate having retic'ulations supported on spacer elements to afford transverse passages and arranged to deflect the upward draft outward a ainst the furnace walls.

2. Apparatus of the class described, including a furnace, a hearth closing in the bottom thereof, and a centrifugal projector rad'ally discharging a composite draft of air adjacent the upper surface of the hearth and oil above the air, said projector and hearth be'ng designed and operating to initiate combustion in a' eripheral zone of im' act and disturbance ofthe projected com oslte draft; and, extending along said perip eral zone, a homogenizing burner of refractory material formed with an upwardly extending wall having inwardly presented impact surfaces adapted to intercept the path of the projected oil and deflect the draft upward, an oil collecting gutter in drainage relation to said impact surfaces, a rear oil collecting gutter behind said wall adrainage passage drainin from said rear gutter to the front of said wall, and are-ignition gas jet in position to be ignited by flame communicated through said passage when normal-operation is discontinued, in combination with an outwardly and downwardly sloping burner plate having reticulations arranged to deflect the upward draft outward against the furnace walls.

3. Apparatus of the class described, in-

eluding a furnace, a hearth closing in the bottom thereof, and a centrifugal projector radially discharging a composite draft of air adjacent the upper surface of the hearth and oil above the air, said projector and hearth being designed and operating to initiate combustlon in a peripheral zone of impact and disturbance of the projected composlte draft; and, extending along said peripheral zone, a homogenizing burner of refractory material formed with an upwardly extending wall having inwardly presented impact surfaces adapted to intercept the path of the projected oil and deflect the draft upward, an oil collecting gutter in drainage relation to said impact surfaces, 9. rear oil collecting gutter behind said wall, a drainage passage draining from said rear gutter to the front of said wall, and a re-' ition gas jet in position to be ignited by ame communicated through said passage when normal operation is discontinued, in combination with an overhanging burner plate supported on spacer elements to afl'ord transverse passages and arranged to deflect the upward draft outward against the furnace walls.

4. Apparatus of the class described, including a furnace, a hearth closing in the bot tom thereof, and a centrifugal projector radially discharging a composite draft of air adjacent the upper surface of the hearth and oil above the air, said projector and hearth being designed and operating to initiate combustion in a peripheral zone of impact and disturbance of the projected composite draft; and, extending along said peripheral zone, a homogenizing burner of refractory material adapted to intercept the path of the projectedoil, an oil collecting gutter in drainage relation to said homogenizing burner, a rear oil collecting gutter behind said burner, a drainage passage draining from said rear gutter to the front of said wall, and a re-ignition gas jet in position to be ignited by flame coml municated through said passage when normal o eration is discontinued 5." pparatus of the class described, in-

-cluding .a furnace, a hearth closing in the bottom thereof, and a centrifugal projector radially discharging a composite draft of air adjacent the upper surface of the hearth and .oil above the air,- said projector and hearth being designed and operating to initiate combustion in a peripheral zone of impact and disturbance o the projected composite draft;

. and, extending along said peripheral zone, a

homogenizing burner of refractory material formed with an upwardl extending wall having inwardly presente impact surfaces adapted to intercept the path of the projected oil and deflect the draft upward an 011 collecting gutter in drainage relation to said upward draft outward against the furnace walls.

-6. Apparatus of the class described, including a furnace, a hearth closing in the bottomthereof, a centrifugal projector radially discharging a composite draft of air adjacent the u per surface of the hearth and oil above the an, and a homogenizing asifying burner of refractory material a jacent the furnace walls, all designed and operating to initiate combustion ina peripheral zone of impact and disturbance of the projected composite draft; said burnerbeing formed with wall elements havin upwardly extending, inwardly presente 1m act surfaces adapted to intercept the path or the projected oil and deflect the draft upward, an 011" collecting gutter in drainage relation to said impact surfaces, said burner having also transverse'passages and an overhanging deflector element arranged to deflect the upward draft outward against the furnace walls.

-7. A paratus of the class described, including a urnace, a hearth closing in the bottom thereof, a centrifugal projector radially discharging a composite draft of air adjacent the upper surface of the hearth and oil above the air, and a homogenizing gasifying burner of refractory material ad acent the furnace walls, all designed and operating to initiate combustion in a peripheral zone of impact and disturbance of the projected composite draft; said burner being formed with wall elements having upwardly extending, inwardly presented impact surfaces adapted to intercept the path of the projected oil and deflect the draft upward, an oil collecting gutter in drainage relation to said impact surfaces, a rear oil collecting gutter behind said burner, a drainage assage drainin from said rear gutter to t e front of sai wall, and a re-i nition gas jet in position to be ignited by ame communicated throu h said passage when normal operation is discontinued. a I

8. Apparatus of the class described, including a furnace, a hearth closing in the bottom thereof, a centrifugal projector radially discharging a composite draft of air adjacent the upper surface of the hearth and oil above the air, and a homogenizing gasifying burner of refractory material ad acent the furnace walls, all designed and operatinguto initiate combustion in a peripheral zone of impact and disturbance of the projected composite draft; said burner being formed with wall elements having upwardly extending, inwardly presented impact surfaces adapted to intercept the path of the projected oil and deflect the draft u ward, a rear oil collecting gutter behind said urner, a drainage passage draining from said rear gutter to the front of said wall, and a re-ignition gas jet in position to be ignited by flame communicated through said passage when normal operation is discontinued. o

9. Apparatus of the class described, in-

cluding a furnace, a hearth closing in the bottom thereof, a centrifugal projector radially discharging a composite draft of air adjacent the u per surface ofthe hearth and oil above the an, and a homogenizing gasifying burner of refractory material ad acent the furnace walls, all designed and operating to initiate combustion in a peripheral zone of impact and disturbance of the projected composite draft; said burner being formed with wall elements having upwardly extending, in-

wardly presented impact surfaces adapted to intercept the path of the projected oil and deflect the draft upward, a rear oil collecting gutter behind said burner, a drainage passage raining from said rear gutter to the front of said wall, and a re-ignition gas jet in position to be ignited by flame communicated through said passage when nermal operationis discontinued; said burner having also transverse passages and an overhanging deflector element arranged to deflect the u ward draft outward against the furnace wa ls.

' 10. Apparatus of the class described, in-

cluding a furnace, aheartli closing in the bottom thereof, a centrifugal projector radially discharging a composite draft of air adjacent the u per surface of the hearth and oil above the air, and a homogenizing asifying burner of refractory material a jacent the'furnace walls, all designed and operating to initiate combustion in a peripheral zone of impact and disturbance of the projected composite draft; said burner being formed l r with wall elements havin upwardly extend-. ing, inwardly presents impact surfaces adapted to intercept the path of the projected oil and deflect the draft upward, a rear oil collecting gutter behind said burner, a drainage passage draining from said rear gutter to the front of said wall, and a re-ignition gas jet in position to be ignited by flame communicated through said passage when normal operation is discontinued; said burner having also an upper deflector element having reticulations arranged to deflect the upward draftoutward against the furnace walls.

11. Apparatus of the class described, including a furnace, a hearth closing in the bottom thereof, a centrifugal projector radis ally discharging a composite draft of air adjacent the upper surface of the hearth and oil above the air, and a homogenizing gasifying burner of refractory material adjacent the furnace walls, all designed and operating to initiate combustion in a peripheral zone of impact and disturbance of the projected composite draft; said burner being formed with wall elements having upwardly extending; inwardly presented impact surfaces adaptedto intercept thepath of the projected oil and deflect the draft upward, a rear oil collecting gutter behind said burner, a drainage passage draining from said rear gutter to the front of said wall, and a re-ignition gas jet in position to be ignited by flame communicated through said passage when normal operation is discontinued; said burner having also an outwardly and downwardly sloping burner plate having reticulations arrange to deflect the upward draw outward against the furnace walls.

12. Apparatus of the; class described, in-

cluding a furnace, a hearth closing in the bottom thereof, a centrifugal projector radially discharging a composite draft of air adjacent the upper surface of the hearth and oil above the air, and a homogenizing gasifying burner of refractory material adjacent the furnace walls, all designed and operating to initiate combustion in a peripheral zone of impact and disturbance of the projected composite draft; said burner being formed with wall elements having upwardly extending, inwardly presented im act surfaces adapted to intercept the path 0 the projected oil and deflect the draft upward, a rear oil collecting gutter behind said burner, a drainage. passage draining from said rear gutter to the front of said wall, and a re-ignition gas jet in position to be ignited by flame communicated through said passage when normal operation is discontinued said burner having also a burner plate having reticula tions through which the draft flows.

13. Apparatus of the class described, including a fire box, a refractory hearth closing in the bottom thereof and a rotary head comprising a centrifugal oil sprayer and an air projector discharging horizontally below the p11 sprayer, above the hearth, said hearth having a substantially unobstructed upper surface lying below the level of normal projection ofthe oil spray, designed and operating to initiate combustion adjacent the periphery of the hearth and the upwardly extending wall of the fire box, said hearth havingad acent the peripheryan upwardly extending refractory ignition wall, a depression at the base of said wall for collecting oil splashing or draining downward fromv the front face thereof and drainage means formed n the wall whereby oil projected bevond the impact face thereof may drain to said front 011 collecting space.

14, Apparatus of the class described, includmg a furnace, a heart closing in the bottom thereof, a centrifugal projector radially d scharging a. composite draft of air ad acent the upper surfaceof the hearth and oil above the air, and a homogenizing gasifying burner of refractory material adjacent thefurnace walls, all designed and operating to nitiate combustion in a peripheral zone of impact and disturbance of the projected composite draft; said burner being formed with wall elements having surfaces adapted to 1ntercept the pathof the projected oil; said'burner having also transverse passages and a deflector element arranged to deflect the upward draft outward against the furnace walls.

15 Apparatus of the class described, including a furnace, a hearth closing in the bottom thereof, a centrifugal projector radially discharging a composite draft of air adjacent the upper surface of the hearth and 011 above the air, and a homogenizing gasifying burner of refractory material adjacent the furnace walls, all designed and operating to initiate combustion in a peripheral gone of impact and disturbance of the projected composite draft: said burner being formed with wall elements having upwardly extending, inwardly presented iinpact surfaces adapted to intercept the path of the pro ected oil and deflect the draft upward. said burner having also a deflector eleinent, arranged to defiect the draft against the furnace walls.

16. Apparatus of the class described, including a furnace, a hearth closing in the bottom. thereof, a centrifugal projector radially discharging a composite draft of air adjacent the upper surface of the hearth and oil above the air, and a homogenizing gasifving burner of refractory material adjacent the furnace walls, all designed and operating to initiate combustion in a peripheral zone of impact and disturbance of the projected composite draft; said burner being performed with wallelements having upwardly extending, inwardly presented impact surfaces adapted to intercept the path of the I adjacent the upper surface of-the hearth and projected oil and deflect the draft upward,

said burner having also an upper deflector element supported by spacing elements to afford transverse passages arranged to deflect the upward draft outward against the furnace walls. I

17. Apparatus of the class described, iiicluding a-furnacc, a. hearth closing in the bottom thereof, a centrifugal projector radially discharging a composite draft of air to initiate combustion in a peripheral zone of impact and disturbance of the projected composite draft; said burner being formed with wall elements having upwardly extending, inwardly presented impact surfaces adapted to intercept the path of the projected oil and deflect the draft upward, said burner having also an upper overhanging deflector element having reticulations supported by spacing elements to afford transverse passages arranged to deflect the upward draft outward against the furnace walls.

18. Apparatus of the class described, including a furnace, a hearth closing, in the bottom thereof, a centrifugal projector radially discharging a composite draft of air oil above the air, and a homogenizing gasify- --ing burner of refractory material adjacent the furnace walls, all designed and operating to initiate combustion in a peripheral zone of inipaet and disturbance of the projected composite draft; said' burner being formed with wall elements having upwardly extending, inwardly presented impact surfaces adapted 'to intercept the path of the projected oil and deflect the draft upward, said burner having also an outwardly'and downwardly slopi burner plate arranged to deflect the upwar draft outward against the furnace walls.

19. Apparatus of the class described, in-

" eluding a furnace, a hearth closing in the bottom thereof, a centrifugal projector radially discharging a composite draft of air adjacent the u per surface of the hearth and oil above the air, and a homogenizing gasifying burner of refractory material adjacent the furnace walls, all designed and operating to initiate combustion in a pripheralzone of impact and disturbance of t e projected composite draft; said burner being formed with wall elements having upwardly extending, inwardly presented impact surfaces adapted to intercept the pathof the projected oil and deflect the draft upward, saidburner having also an outwardly and downwardly sloping burner plate having reticulations arranged to deflect the u ward draft outward against the furnace wa Is.

20. Apparatus of the class described, in-

cluding a furnace, a hearth closing in the above said impact surfaces ments to afford transverse passages arranged fying burner of refractory material adjacent the furnace walls, all designed and operating to initiate combustion in a peripheral zone of impact and disturbance of the projected composite draft; said burner being formed with wall elements having upwardly extending,

inwardly presented impact surfaces adapted to intercept the path of the projected oil and deflect the draft'upward, said burner having also passages for permitting outward flow of the draft, and a burner late supported y spacing eleto direct the upward draft outward against the furnace walls.

21. Apparatus of;the class described, in-

eluding a furnace, a hearth closing in the bottom thereof, a centrifugal projector radially discharging a composite draft of air adjacent the upper surface of the hearth and oil above the air, and a homogenizinggasifying burner of refractory material a jacent thefurnace walls,- all designed and operating to initiate combustion in a peripheral zone of impact and disturbance of the'projected composite draft; said-burner being formed with wall elements having upwardly extending, inwardly presented .im act surfaces.

adapted to intercept the path 0 the projected 011 and deflect the draft upward, said burner having also a supplemental to afford transverse passages arranged to direct the draft against the furnace walls.-

plate having 'retlculations supported by spacing elements 22. Apparatus of the class described, in-.-

cluding a fire box, a refractory hearth closing in the bottom thereof anda rotary head comprising a centrifugal. oil ,sprayer and an air projector discharging horizontally below the oilsprayer, above the hearth, said hearth having a substantially unobstructed upper surface lyingbelow the level of normal projection-of the oil spray, designed and operatmg to initiate combustion adjacent the periphery of the hearth and the upwardly ex-' tending wall of the fire box, said hearth havin adjacent theperiphery an upwardly exten ing refractoryignition wall and above said wall a plate element and supports therefor, adapte to intercept oil pro ected by the projecting means.

23. Apparatus of the class described, including a fire box, a refractory hearth closing in the ottom thereof and a rotary head comprising a centrifugal oil sprayer and an air projector discharging horizontally below the oil sprayer, above the hearth, said hearth having a substantially unobstructed upper surface lying below the level of normal projection of the oil spray, designed and operating to initiate combustion adjacent the pe- 24. Apparatus of the class described, in-

cludin a fire box, a refractory hearth closing in the ottom thereof and a rotary head comprising a centrifugal oil sprayer and an air projector discharging horlzontally below the oil sprayer, above the hearth, said hearth having a substantially unobstructed upper surface lying below the level of normal projection of the oil spray, designed and operatingto initiate combustion ad acent the periphery of the hearth and the upwardly extending wall of the fire box, said hearth havin adjacent the periphery an upwardly exten ing refractory ignition wall and above said wall a plate element and supports therefor, adapted to intercept oil pro ected by the projecting means, and said plate element and the upper surface of said 'wall draining outward toward the periphery.

25. Apparatus of the class described, in cluding a fire box, a refractory hearth closing in the bottom thereof and a rotary head comprising a centrifugal oil and air projector discharging above the hearth, said hearth having a substantially unobstructed upper surface lying below the level of normal projection of the oil spray, said hearth having adjacent the periphery a refractory wall with spaced-apart projections extending upwardly above said level, said wall being arranged to afford impact surfaces in the path of said spra and other surfaces presented rearwardly a j acent the wall of the fire box, and sup plemental refractory surfaces in reverberatory relation to said rear face of said impact wall and formed to afford spaced-apart paths for escape of flame and combustible mixture outward toward said fire box wall.

26. Apparatus of the class described, including a fire box, a refractory hearth closing in the bottom thereof and a rotary head comprising a centrifugal oil and air projector discharging above the hearth, said hearth having a substantially unobstructed upper surface lying below the level of normal pro-. jection of the oil spray, said hearth having adjacent the periphery a refractory wall with spaced apart rojections extending upwardly abovesaid evel, said refractory wall being arranged to afford impact surfaces in the path of said spray and surfaces presentpjd rearwardly ad acent the wall of the fire 27. Apparatus of the class described, including a fire box, a refractory hearth closing in the bottom thereof and a rotary head comprising a centrifugal oil andv air projector discharging above the hearth, said hearth having a substantially unobstructed upper surface lying below the level of normal pr0- jection of the oil spray, said hearth having adjacent the periphery an upwardly extend.- ing refractory impact wall, a rearwardly extending face of which is adjacent but spaced apart from the fire box wall, in combination with a member affording supplemental refractory surfaces in reverberatory relation to said rearwardly extending face of said impact wall and affording spaced apart paths for escape of flame and combustible mixture from the reverberatory space into contact with the wall of the fire box.

28 Apparatus of the class described, includlng afire box, a refractory hearth closing in the bottom thereof and a rotary head i comprising a centrifugal oil and air proector discharging above the hearth, all designed and operated to precipitate combustion adjacent the periphery of the hearth, in combination with a refractory wall adjacent the periphery of the hearth, said wall including a face for impact of the spray and upward deflection of the draft, and another face which extends toward the fire box wall, together with a cooperating member affording supplemental refractory surfaces above and in reverberatory relation to the latter face of said impact Wall and formed with s aced-apart passages for through flow of ame and combustible mixture from the reverberatory space outward and upward to ward the wall of the firebox.

29. Apparatus of the class described, in-

tor discharging above the hearth, all designed and operated to precipitate combustion adjacent the periphery of the hearth, in combination with a refractory wallv adjacent the periphery of the hearth, said wall including a lowerimpact portion or element adapted to deflect the draft upwardly, and an upper spaced-apart portion afl'ording rearwardly and downwardly inclined deflecting surfaces and formed and arranged to afford spaced-apart paths for rearward and upward escape of flame and combustible mixture toward the wall of said fire box.

30. Apparatus of'the class described, including a fire box, a refractory hearth closing the bottom thereof and a rotar head comprising a centrifugal oil and an projector discharging above the hearth, said projector being 0 the high speed type "and said hearth having a substantially unobstructed upper surface lyingbelow the level of normal projection of the oil spray, said hearth having adjacent the periphery elements extendin upwardly above said level arranged to a 0rd impact surfaces in the' path of said spra said elements including deflect the spra downwardl and outward- 1y, said incline elements bemg formed and arranged to afford spaced a art paths for escape of flame and combustib e mixture outwardly toward the wall of said fire box.

31. Apparatus of the class described, including a fire box, a refractory hearth closing in the bottom thereof and a rotary head comprising a centrifugal oil and air projector discharging above the hearth, said projector being of the high speed type and said hearth having a substantially unobstructed upper surface lyin below the level of normal projection of t e oil spray, said hearth having adjacent the periphery refractory elements presenting upwardly and inwardly inclined surfaces and formed with passages for outward and upward through flow of flame and combustible mixture.

Apparatus of the class described, including a fire box, a refractory hearth closing in the bottom thereof and a rotary head comprising a centrifugal oil and air projector discharging above the hearth, all designed and operated to precipitate combustion adjacent the periphery of the hearth, in combination with a refractory combustion precipitating structure adjacent the periphery of the hearth, in the path of the spray and air draft, said structure including an impact portion or element ada ted to deflect the draft upwardly, and space apart refractory surfaces in reverberatory proximity and formed and arranged to afford paths for escape of flame and combustible mixture toward the wall of said fire box.

33. Apparatus 0f the class described, including a fire box, a refractory hearth closing in the bottom thereof and a rotary head comprising a centrifugal oil and air projector discharging above the hearth, all designed and operated to preci itate combustion adjacent the periphery o the hearth, .in combination with a refractory combustion precipitating structure adjacent the periphery of the hearth, in the path of the spray and air draft, said structure including spaced-apart refractory surfaces in reverberatory proximity and formed and arranged to afford paths for escape o flame and combustible mixture toward the wall of said fire box.

34. A flame concentrator and director of the character described, including a grill having a flame-directing aperture, a deflecting wall extending upwardly toward said aperture, a deflecting surface in front of said wall adapted to deflect an impinging draft upwardly into a draft passing above said deflecting surface toward said deflecting wall, and a mixing valley intermediate said deflecting wall and deflecting surface.

35. A flame concentrator and director of the character described, including a rill having a flame-directing aperture, a de ecting wall extending upwardly toward said aperture, a deflecting surface in front of said w'all adapted to deflect an impinging draft upwardly into a draft passing above said deflecting surface toward said deflecting wall, and a vertical deflecting surface, extending transversely of said deflecting walkintermediate said wall and aperture. 2

36. A flame concentrator and director of the character described, including a grill having a flame-directing aperture, a deflecting bers adapted to be disposed and supported in any selected places on the grill support, whereby the spacing of the grill members from each other may be varied, said grill members having flat inclined a ertured portions disposed above the surface of the hearth when the grill members are disposed on the grill support.

38. In a fire box for oil burners of the character described, in combination, a substantially annular hearth, and flame deflecting and concentrating grill members disposed on the hearth adjacent its periphery, said grill members having flat apertured portions inclining upwardly toward the center of the hearth and spaced flat vertical supporting walls or flanges beneath said flat portions directed approximately endwise toward the center of the hearth.

39. In a fire box for oil burners of the character described, in combination, a substantially annular hearth, flame deflecting and' act an. impinging draft up concentrating grill members disposed on the hearth adjacent its periphery, said grill members having flat apertured portionsinclinin upwardly toward the center of the hearth an spaced flat vertical supporting walls or flanges beneath said flat portions directed approximatel endwise toward the center of the hearth, an an a proximately annular grill support dispose on the hearth, said grill members being supported thereon.

40. In a fire box for oil burners of the character described, in combination, a substantially annular hearth, flame deflecting and concentrating grill members disposed on the hearth adjacent its periphery, said grill memeeann support comprising supporting units having deflecting surfaces facing toward the center of the hearth and adapted to deflect an impinging draft u wardly to and through the apertures of sai grill members. 41. A fire box construction for oil burning furnaces of those types which are provide 15 with centrifugally-acting distributing head? includin a hearth extending around sai distributing head at a considerable distance therefrom and including an upstanding. portion having an inner surfacewhich intersects the trajectory of fuel droplets at substantially right angles, and an inwardly upwardly inclined portion overhanging said inner sur face; and an inner, upwardly extending projection spaced a short distance from said upstanding portion and terminating below the trajectory of the fuel droplets and defining 7 between 1tself and said upstanding portion a narrow depression adjacent the lower edge of 30 said surface.

furnaces of those types which. are provided with centrifugall -actin distributing heads,

including, a heart exten ing around said dis- 1 tributing head at a considerable distance therefrom and including an upstanding por tion having an inner surface which intersects the trajectory of fuel droplets at substantially right angles, andan inwardly upwardly ifnclined portion overhanging said inner surace.

Signed at New York cit in the county of New York and State of ew York this 9thday of February, A. D. 1928. Y

. FORREST A HEATH.

42. A fire box construction for oil burning 

